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David Wolber is a Professor of Computer Science at the University of San Francisco. He is the author of App Inventor 2: Create your own Android apps along with Hal Abelson, Ellen Spertus and Liz Looney from the App Inventor team, and he runs appinventor.org which provides on-line, video-based teaching lessons.

David began teaching App Inventor as part of Google’s 2009 pilot program involving ten universities. He’s received grants from Google and the W.M. Keck Foundation to support his work and is part of an NSF grant on teaching computational thinking with App Inventor. David served part of his sabbatical at MIT in 2014 and has regularly contributed to the App Inventor project.

hello prof. Wolber, I’m trying to make a app that reads a list of musics but i can’t make it to go to next music without pressing play button again, my question is: is there a way in app inventor to play all the musics in the list and at the end go to start again?
thanks

My nine-year-old and I have been going through the tutorials, and we both can follow along easily and understand the logic and reasoning behind the various pieces. Thank you so much for the great work and contribution to the Android and programming communities. Hopefully we’ll have something useful to contribute as well.

For now though, we’re just having fun. My six-year-old is anxious to get in on the action. She wants a horse you can pet that will neigh. And the nine-year-old is anxious to associate incorrect sounds with all sorts of animlas. He wants a much longer baseball quiz too – with players he knows. It has been great fun! Like I said, hopefully we’ll have something useful to contribute eventually. 🙂

It’s great to see kids looking at computer programming as fun. Bestselling author Daniel Pink would be excited to know you’ve come up with a way to make computer programming a play-like activity for elementary school kids (and adults).

Matt and Alex, thanks for your kind words– they really made my day. I’ve been working hard on tutorials and a book we’re trying to complete, and its really nice to hear my work is helping people. I’ll pass your note to the Googlers on the App Inventor team– we all love to hear about kids having fun and building things (they may try to snatch the kids up as software engineers!)

First I am 13, taking an app inventor class(at a college called DigiPen) and we are learning a lot about electronics(we built a speaker!) and are using app inventor a lot. Your tutorials helped a lot when I am working at home on new projects. I am currently trying to make a new project called Space Invaders like the game completely on my own and i want to know if there is a way so that when I press the fire button, it will shoot(it already shoots and “deletes” bullets when it gets to the edge of screen) but I want there to be a way so that the fire button can make more then one bullet on the screen(in multiple shots) but so that when you press it a second time when first bullet is still on screen it makes a new bullet and doesn’t just reset the first bullet. Thanks so much for you extremely helpful and super positive tutorials! 🙂

Hi Alex. Here’s one scheme for having multiple bullets in
a shooting game.

1. Create multiple imagesprites, say five, one for each bullet.
2. Make all of them invisible to start
3. Keep a variable bulletNumber. It starts out as 1. 1 is associated with bulletSprite1
2 with bulletSprite2, etc. When shoot button is clicked, use an if to check the bulletNumber,
and make the right bullet visible and locate it at the right place.
4. You might want to use imageSprite animation (direction, speed properties) instead of clock timers for this one.
5. In events like collidedwith, You can use if statements to check which bullet was hit. An alternative is to use
the AdvancedComponents tab, which allows you to generically do things to imageSprites.

This is what Computing should be all about…the average Joe being able to Program his Computer the way in which it serves him best and not always needing a For-Profit Corporation to dictate his options.
I suggested a similar type of interface to Apple thirty years ago! Alas…I wasn’t a Programmer…LoL

Love the site, and the tutorials. 🙂
Is there any timeframe where we can expect to see appinventor apps being supported for import into eclipse? I’d love to see the source code for some of your apps and use the functionality to experiment with my own stuff in the android sdk/eclipse environment!

Hi Phil and thanks. I don’t believe Java/Android SDK code generation is in the immediate App Inventor plans though it is definitely a point of discussion. For now, the only way to connect to code and the web is through the TinyWebDB component (see my site appinventorapi.com).

Hi David, sorry I’m slightly confused, why mentioned the TinyWebDB component? How is this benefical? I read over it on your site and don’t see how it relates to my question. It’s a shame you cannot export to eclipse. 😦 How difficulut would it be to write Android, where’s my car for example in java? (assuming you are familiar enough with java!)

Philip! Yea I didn’t follow the “TinyWebDB part” either, but I wasn’t going to say anything. Maybe he meant that even if you could get the generated code for the app, and the code was java, and the code was not crazy looking, and had comments, you still could not get it off the phone as the only mechanism is webDb.

This is what you were asking: wouldn’t it be great to be able to import the code into Eclipse, after saving the java text to, say, the SD card.

It is a natural idea, and I feel confident that it will happen, and I expect that Eclipse (which I know noting about) will adopt an optional AI coding feature: you could view code, or selected portions, as blocks as text.

Thank you for the fantastic site and all of the hard work. I received my invitation for app inventor earlier this week and finally had the chance to install the necessary tools on my computer and HTC Incredible earlier today.

I’m a full time physician with an idea for developing an ap to assist my patients. Before I received the invitation to app inventor I was slowly teaching myself Java and C++ via books and online tutorials.

My question for you is this… Do you think it is wise to “dabble” in multiple programming languages if I am seeking to develop an app as a hobby? I’ll be honest I’m leaning toward the multipronged approach.

Already, there are tricks I’ve learned in C++ (particularly in manipulating the command line) which have been helpful in Java tutorials and for installing the Android SDK.

Hi Dr. Onyelja. I definitely think the programming concepts you learn in one language transfer easily to another. Sometimes early on its good to focus on one language so as to concentrate on those concepts and not get bogged down with syntax and language differences.

I’d love to hear your ideas on app for patients. We are gearing up for final projects and I’m sure my students would be interested.

I just spent the last 2 hours completing the Basic Tutorials at App Inventor. Not being a programmer hasn’t slowed me a bit, thanks to the wonderful lessons. Just seeing the results play out on the connected phone is enough to get anyone giddy with excitement.

I teach an Engineering/Design class to 9th graders in NYC. We focus on the design process, problem solving, and teamwork in the context of a design challenge (i.e. build the slowest parachute, design a home for a post-quake Haiti). I’ve been thinking about doing an app design challenge next term. Do you think ninth graders could develop enough skill with app inventor for groups to design their own apps? How long would it take them to get to this level?

Thank you very much for your tutorial. I would like to use a Zigbee communication and I have found a USB Zigbee stick with Linux driver. Do you have any tips to send and receive commands and data using App Inventor?

Hi David, I am from Honduras in Central america and I am learning about Android programming, I would like to make a variation of “NoTextWhileDriving”, something like “NoCallsWhileDriving” , “Meeting”, “Sleeping” or something, do you know if that is posible from AppInventor, becouse y dont find the options in “PhoneCall1”, I am sorry to bother you, thanks for your time, good job.

Hi David Im independent inventor.Im looking for a costomer license my invention.I just got non provisional number from USPTO.The idea is to simplify and cheaper for the consumer.The main idea, Intercom-to-cell phone communication from a distance.An entry intercom, controller system that uses a regular phone line.A microphone ,speakerand camera allow the intercom to communicate with a cell phone(Apple iphone).You can check what is going on at the place from a cell phone from a distance by calling there and listening in via the microphone,watching via the camera. Intercom (controller) will send SMS or special signal to cell phone in case of an emergency if any signal from security sensor, or other optional devices.

I have built an app using appinventor for calculating and sharing a person’s carbon footprint on Twitter. I wanted to extend it to Facebook ie. post on Wall with friends. I am unable to proceed on how can I do the same. Could you please help? Is there any tutorial or method to do the same?

Hi Parashar. Unfortunately, there’s no Facebook component. The only way to hook into Facebook from App Inventor is to create an App-Inventor-Compliant API. See my site appinventorapi.com for instructions.

Thanks for sharing the website. I will check it out. If am successful in building one before AI team releases it, I will share it. I am a novice in Python and PHP but will still try it.
An alternative which I was thinking, is there anyway to use Activitystarter to invoke the Facebook app installed on the phone? If you have any thoughts on the same, could you please share.

I just some days ago found out about app inventor and want to know if it is possible to create a service in app inventor, its an app but it wouldn’t have a screen, interface. like a background application.

Professor Wolber
I really like the text you have written for the app inventor. I am doing a little translation for the text (into chinese) so that I can share your ideas/knowledge with my friends.

I do hope to try build a simple app myself. I hope it can render the forum i visited often into a mobile version. The website does have RSS feeds for different sub-forum. So someone suggests that I can use what they call RSS feed reader. I am not sure what app inventor can do in that. I understand I should first get a template, then fill it with the content generated by RSS feed.
Could u give me a few instructions on where to start (if the app inventor can create something enough just for that purpose)? I am quite amateur in programing but don’t mind trying to learn something new.

I love your tutorials. I have done almost all of them. I am really interested in the Workout app tutorial. Any idea when it will be completed? i think there are some definitions missing. And without pics I am starting to get lost.
this is the one i am talking about:http://www.appinventor.org/workout-tutorial

My 9yr old daughter just bought a hacked pandigital 7″ tablet for $120. Thanks to you, google, and slatedroid she’ll soon be writing her own apps on it and learning how fun software development can be once you learn the tools. This reminds me of how fun it was to work through the applesoft basic tutorials in the early 80’s when I was in high school and apple liked to share all information about their products. The app inventor environment is going to revolutionize programming and help elementary school kids learn math through play.

David,
Great work!! I have been learning from your tutorials. I see your books is listed in Amazon, but not released yet. When will this be out? Also will there be further information for bluetooth integration in the book. I see that components are available, but to-date I do not see any good tutorials (for novice like me). If you have any further insight on this I would appreciate it. Keep up the good work. Best regards,
Dave

I am a grad student taking classes of eclipse and now app inventor and I went to take all of your useful tutorials. I do have a question in regards on how to create a register form or a sign up form once you open the app. The reason I need this is because I need to save users database into tinyDB and then be able to use the telephone numbers stored in it. Can you write a question and be sent out to a specific user once that person is registered with the app?

Hi Jimmy. The SpeechRecognizer component is not bad– you’ll find it in the “other stuff” folder. Put an if block within the SpeechRecognizer.AfterGettingText event handler, and if the “result” matches some word you’re looking for, play a sound file.

I love Appinventor, but I’m finding that the Apps once installed on the phone open slowly. Is there a way to speed up load times? I’m finding apps that are about 4mb take about 8 to 10 seconds to load. Once they load, they operate fast..

Great tutorial, thanks! I’ve a question for you professor, a doubt about tinywebdb component: if i use the same app (which uses tinywebdn) on different phone and so the component point to the same db url, how the app recognize the data to pick from db? Are they marked as provenient from different devices so the app knows what to use? So, if on the phone A i save “Kevin” in the “name” tag, and on the phone B i save “John”, which data i will find on the db? Both? Or just John? Sorry for bad explanation, hope it’s understandable… thanks

If you use the same app from two devices, they both will access the same data, unless the program changes the tag during execution. If the programs change the tags to use different tags, they will access different records.

Hi, thanks for the tutorials and great teaching. I wanted to make a program that allows me to speak input to text. Saving the text to a google spreadsheet. The text to speech tutorial is nice but is there a tutorial showing the speak to text and saving as a list or output to other google apps or files.

Hi Dana. Sounds cool. There is now a component for using Fusion tables– you might want to use it to store the output. You could also use the new Web component. Unfortunately, I don’t yet have tutorials for these or for speak to text.

Hello Sir, i’m just read and follow Quiz Me tutorial. At this paragraph

“The problem with the app is that it always increments the currentQuestionIndex variable when the NextButton is clicked. When currentQuestionIndex is already 3 and the user clicks the NextButton, the app changes currentQuestionIndex from 3 to 4, then calls select list item to get the currentQuestionIndexth, or in this case, the 4th item. Since there are only three items in the variable QuestionList, Android complains.

What the app needs to do is ask a question– check a condition– when the NextButton is clicked, and execute different blocks dependending on the answer. One way to ask the question is to ask, “is the variable currentQuestionIndex already 3?” If the answer is yes, you should set currentQuestionIndex back to 0 so the user is taken back to the first question.”

When i use “if test-then do” block my “next” button didn’t work after that, but if i change with “ifelse” block it works just fine.

Can you explain that? are there somethings that i forget? Can you reply to my email please? Thank for your attention sir

Awesome, fantastic! I followed the course in July, and built a great app already. Due to the discontinuing I switched to Eclipse and the Android SDK, but I hate to do the programming, despite the fact that I’m a programmer for more than 25 years. Regards, Sjaak.

Is AppInventor is suitable for developing apps for my Nexus7 tablet, or if I should go down the Java SDK/Eclipse route? I’ve just ordered a Nexus7 tablet and want to do some simple app development with my 12yo son, so I’m just wondering if AppInventor apps will work on the Nexus7, ie. will the apps work with new JellyBean version of android?

Hi David! I am using the textbook chapters to teach a summer institute on mobile apps for a one week course for high school students. And I wanted to let you know that I think we found a missed item in the textbook in Chapter 7: Android, Where’s My Car?. I believe that Table 7-1 fails to include an item. Component type: label, palette group: basic, What you’ll name it: ?, and purpose: display the text “Address:”. Please correct me if I am wrong, but I believe this necessary for the label “Address:” to appear in the Remember Address location.

Also, thank you for this book. The students and I are enjoying it and it is also helpful to my college students as well!

Hello
The last Days I tried to learn how the app inventor works and did many of your tutorials. Now I’m at the Quiz and Answer App with the TinyWebDB.

My Problem ist, i want to change the Quiz to a Chat. It works, but all new messages appear at the bottom – But I want them on the top (so its not an endless long chat). But I don’t know how this could be done. An alternative could be, that after 5-10 messages the old ones get deleted, but I also don’t know how this could work… :l

I have a question about, playing videos on the webviewer, according to your post (http://www.appinventor.org/media-editing) the only possible way to view videos is with the use of the ActivityStarter component. Right now I’m building a simple browser app and I have everything set to go, the only thing I’m missing are playing media objects on the webviewer (e.g. videos on youtube), you said that the activity starter is the only way but I can’t seem to figure out where to attach it, there’s no if Link in webviewer is clicked block where I can put the command call activitystarter.startactivity, so I made a little test, I made a button (a play button) where its set to playbutton.click->set activitystarter.dataUri to webviewer.currentURL->call activitystarter.startactivity and it works, it plays the video, but what happens is that it opens the phones built-in browser and you play the video from there, which is kinda off because I want users to use my browser not the built in phone browser.

So what I’m trying to say is how can I play the video when the user presses the play video on the webviewer? Where do I attach the startactivity block when there is no if links or media files on webviewer is click block to attach it on.

Howdy would you mind stating which blog platform you’re working with? I’m looking to start my own
blog soon but I’m having a hard time choosing between BlogEngine/Wordpress/B2evolution and Drupal. The reason I ask is because your layout seems different then most blogs and I’m
looking for something completely unique. P.S Apologies for getting off-topic but I had to ask!

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hello prof. Wolber,
its really nice to read your book on app inventor.
one of the examples here on following link I have started to build in app inventor and made up o the first video and made the .apk file and got at my galaxy tab2 7.0 mobile. while the sms is received, nothing happens in the return a caption raised in my mobile as — : id : “unable to start GV helper”.
cant understand this as I am novice to app inventor can you please guide whats going wrong sir.

Hello
I am just beginning to use app inventor with my class however they can’t seem to download to their actual phones. One of the students says it is not recognising an android 4 or later phone? Is this correct?

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hi,
issue with my app inventor. i have a simple quiz app, but the third an final question is a problem. for every answer, when the correct answer is inputted, it comes up with correct.. however on the last question.. it seems to always output incorrect (even when correct), followed by the emulator crashing as a result due to some number absence or something like that. this is part of my GCSE coursework so i would appreciate a reply as soon as possible.

Note: Head of department and nearly anybody with any qualification cannot find an issue with the block program

Hii David,
Its great work we can seen from App inventor.i feel its magic.
Im learning to build apps with App inventor.
I find the apps created are functioning only when it is open only in the foreground,even the screen locks, its not functioning .But practically we cannot open the app always.How to overcome this by make the app always run in the background until unless user stop the app or it should open/start automatically with some trigger like when SMS received.
How can be achieved with App inventor.Pls help

I’m really enjoying the design and layout of your website.
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Hi, I’am a chinese guy, and I have read all of the demo and cource in appinventor.org. It’s a great book about starter, I want tanslate it and import the book to chinese reader, is there some way to do this ?
Thank you!

Hi David,
I just started with app inventor and enjoy it. However, confused with table 11.1 in BroadcastHub. There are four labels required in the user interface – Label2 is called BroadcastListLabel and the actual Label3 is called Label2. Please help. Thanks !

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Hello. I am a student who likes App Inventor. I downed make the app does not recall the moment the capacity of the apps over 11mb apk. I was so sorry in the limits of the capacity to create a variety of apps I want. Do you want to spend more than 11mb capacity if you ever would like to have the developer pay to register. Please mail back.

Hello, I was wondering if you could help me? I’m new to app inventer and I want to make a quiz that displays the question and also reads it out, I don’t know how to do this and I have done a lot of your tutorials but still don’t understand it? I also need to add a timer so if they don’t answer in 30 seconds it goes to game over and try again.

Hi David,
I am a teacher at a girls school.
We need an app for the girls to which i can push notices to remind them to check deadlines and new notes.
I have reviewed many of the App inventor sites but have not been successful. Also most of the tinyweb links are dead.
I have seen the texting function but that seems to work on phone numbers which would not be usable with approx. 1000 recipients.
If push notices are not possible would you send to me the block config for RSS please. I see mention of it but again dead links.
sorry to bother you but …..
thanks
philphilip.devitt@det.nsw.edu.au